Caleffi Brass Air Relief Valve Fitting:CALEFFI 15MM (1/2") MI BRASS AIR RELIEF VALVE It features an LED filter

It features an LED filter tap that turns from blue to red when the filter cartridge needs replacing

Connects everything together nicely

All female threads 1 1/4" and greater are supplied with a stainless steel reinforcing ring

5V AA alkaline batteries (included)

Custom designs can be designed and supplied

Caleffi Brass Air Relief Valve Fitting:CALEFFI 15MM (1/2") MI BRASS AIR RELIEF VALVE It features an LED filterThese automatic air vents eliminate residual air in heating and air conditioning systems without the need for manual intervention. This prevents undesired noise, wear of devices in the circuits and inefficient performance of heating units. Installation Air is vented from the system by turning the plug on the air outlet anticlockwise by one complete turn from the fully closed position. Air is automatically vented if the cap is kept in this position. It